Notification app : disable swipe when the app is in 'preview' mode. In this mode, only the new notification should be displayed, there is no point to allow navigating to past notifications.

Works as a workaround for the crash that occurs when you swipe the notification app in preview mode (https://github.com/JF002/InfiniTime/issues/250).

src/displayapp/screens/Notifications.cpp

@@ -73,6 +73,8 @@ bool Notifications::Refresh() {
 }
 
 bool Notifications::OnTouchEvent(Pinetime::Applications::TouchEvents event) {
+  if(mode != Modes::Normal) return true;
+
   switch (event) {
     case Pinetime::Applications::TouchEvents::SwipeUp: {
       Controllers::NotificationManager::Notification previousNotification;